These Help pages can be downloaded here with the Winning Bridge Shareware game for Microsoft Windows 98, ME, 2000 and XP.
If you would rather read a book, take a look at the Help Index page for some suggestions.
Gerber Convention
To use the Gerber convention selected the Gerber option in the Conventions Dialog.
The Gerber convention allows a player to ask how many aces their partner holds.
To start Gerber a player bids 4 clubs, their partner then bids:
0 or 4 aces: 4 diamonds
1 ace: 4 hearts
2 aces: 4 spades
3 aces: 4 no trumps
It is then possible to ask for kings by bidding 5 clubs with similar responses at the five level.